1. Field of the Invention
The present invention relates to a punching device that punches a hole in a sheet of paper, a sheet processing apparatus and an image forming apparatus that include the punching device.
2. Description of the Related Art
In a general punching device that punches a hole in a sheet of paper, punch waste, which is a chad of paper generated upon punching, falls freely and is accumulated in a mountain form in a collection container collecting the punch waste. Thus, even when a top of the mountain of the accumulated punch waste reaches a height of the collection container, there remains space around peripheral walls of the collection container that are positioned farther from the top, which lowers the efficiency of collecting punch waste in the collection container. When the efficiency of collecting punch waste in the collection container is lowered, it becomes necessary to frequently dispose punch waste collected in the collection container, thereby deteriorating maintenance conditions.
In the punching device described in Japanese Patent No. 3648356, the collection container is provided therein with a guiding member that has shaft members fixed, at both ends thereof, to inner walls facing each other in the collection container, and roof-formed plate members provided substantially perpendicular to an axis direction of the shaft member and extended diagonally downward to both sides of the shaft member with the shaft member as a top line. With such a guiding member, punch waste falling onto one of inclined faces of the plate member and moving along the inclined face, punch waste falling onto the other inclined face of the plate member and moving along the inclined face, and punch waste falling not onto any of the inclined faces of the plate member, are dispersedly collected in the collection container. In this way, punch waste is dispersedly collected in the collection container by the guiding member, and a depositional surface of the punch waste accumulated in the collection container is a moderately inclined face in a substantially planer state. Thus, it is possible to substantially fill the collection container with punch waste while leaving little space, thereby improving the efficiency of collecting punch waste.
However, scattering directions of punch waste generated upon punching are varied, and thus when only a small amount of punch waste falls on the inclined faces of the plate member, the punch waste is not sufficiently dispersed in the collection container by the guiding member. Consequently, there occurs a problem in which the efficiency of collecting punch waste cannot be improved sufficiently.
Therefore, there is a need for a punching device capable of improving the efficiency of collecting a chad of paper to a collection container, as compared with the conventional punching device, a paper processing apparatus and an image forming apparatus that include the punching device.